Molecular phylogeny provides new insights on the taxonomy and composition of Lyperosomum Looss, 1899 (Digenea, Dicrocoeliidae) and related genera

Abstract

Lyperosomum Looss, 1899 is one of the largest genera of the Dicrocoeliidae and is one of the best examples of the systematic complexity and taxonomic instability within this family. We present the molecular analyses based on novel sequences of nuclear and mitochondrial genes obtained from 56 isolates of adult flukes and larval stages of dicrocoeliids belonging to Lyperosomum, Skrjabinus, Zonorchis as well as previously available sequence data. According to obtained results we propose to return Zonorchis clathratus and Z. petiolatus into Lyperosomum, and to recognize L. alagesi as a synonym of L. petiolatum. Our study shows that L. petiolatum commonly occurs in Europe in corvids as well as in several species of migratory songbirds, e.g. Sylvia atricapilla. At the same time, the Turdidae appear to host a distinct species of Lyperosomum. The phylogenetic analysis has clearly demonstrated the paraphylepic nature of Lyperosomum and indicated the need of its thorough revision preferably using specimens from type hosts and type territories of nominal species. In addition, inclusion of numerous not yet sequenced dicrocoeliid genera into future phylogenetic studies is necessary to clarify the interrelationships of taxa within the family and stabilize its system.

Graphical abstract

Highlights

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  Significant discord exists between molecular data and current taxonomy of Lyperosomum.

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  Phylogenetic relationships of Lyperosomum, Skrjabinus and Zonorchis were studied.

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  Lyperosomum is a paraphyletic taxon.

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  Re-evaluation of morphological criteria used in dicrocoeliid systematics is needed.

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  Life cycle of Lyperosomum petiolatum is elucidated for the first time in the nature.